blue/.blue/docs/rfcs/0014-workflow-enforcement-parity.impl.md

RFC 0014: Workflow Enforcement Parity

Status	Implemented
Date	2026-01-25
Reference	coherence-mcp workflow patterns

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Summary

Blue's RFC workflow lacks enforcement patterns that coherence-mcp implements effectively. When an RFC is accepted, the current implementation returns a next_action JSON field that tools may ignore. Coherence-mcp instead uses conversational hints and gating requirements that create a more reliable workflow.

Problem

When RFC 0015 was accepted, no worktree was created. The response included:

"next_action": {
    "tool": "blue_worktree_create",
    "args": { "title": "..." },
    "hint": "Create a worktree to start implementation"
}

But this metadata was not acted upon. The workflow broke silently.

Root Causes

1. No plan requirement - Blue allows worktree creation for RFCs without plans
2. Weak hints - next_action is machine-readable but not conversational
3. No state machine - Status transitions aren't validated formally
4. No gating - Can skip steps (accept → implement without worktree)

Proposal

Adopt coherence-mcp's workflow patterns:

1. Conversational Hints

Change handle_rfc_update_status to include conversational prompts:

let hint = match status {
    "accepted" => Some(
        "RFC accepted. Ask the user: 'Ready to begin implementation? \
         I'll create a worktree and set up the environment.'"
    ),
    "in-progress" => Some(
        "Implementation started. Work in the worktree, mark plan tasks \
         as you complete them."
    ),
    "implemented" => Some(
        "Implementation complete. Ask the user: 'Ready to create a PR?'"
    ),
    _ => None,
};

2. Plan Enforcement

Gate worktree creation on having a plan:

// In handle_worktree_create
let tasks = state.store.get_tasks(doc_id)?;
if tasks.is_empty() {
    return Ok(json!({
        "status": "error",
        "message": "RFC needs a plan before creating worktree",
        "next_action": {
            "tool": "blue_rfc_plan",
            "hint": "Create a plan first with implementation tasks"
        }
    }));
}

3. Status State Machine

Add formal validation in blue_core::workflow:

pub enum RfcStatus {
    Draft,
    Accepted,
    InProgress,
    Implemented,
    Superseded,
}

impl RfcStatus {
    pub fn can_transition_to(&self, to: RfcStatus) -> Result<(), WorkflowError> {
        let valid = matches!(
            (self, to),
            (Self::Draft, Self::Accepted)
                | (Self::Draft, Self::Superseded)
                | (Self::Accepted, Self::InProgress)
                | (Self::Accepted, Self::Superseded)
                | (Self::InProgress, Self::Implemented)
                | (Self::InProgress, Self::Superseded)
                | (Self::Implemented, Self::Superseded)
        );
        if valid { Ok(()) } else { Err(WorkflowError::InvalidTransition) }
    }
}

4. Workflow Gating

Action	Requires
worktree_create	RFC accepted + has plan
rfc_complete	RFC in-progress + 70% tasks done
pr_create	RFC implemented + worktree exists

Implementation Tasks

1. Add RfcStatus enum and state machine to blue-core
2. Update handle_rfc_update_status with conversational hints
3. Add plan check to handle_worktree_create
4. Add gating validation to PR creation
5. Update tests for new validation

Files Changed

• crates/blue-core/src/workflow.rs (new)
• crates/blue-mcp/src/server.rs (update status handler)
• crates/blue-mcp/src/handlers/worktree.rs (add plan check)
• crates/blue-mcp/src/handlers/pr.rs (add worktree check)

Test Plan

• State machine rejects invalid transitions (draft → implemented)
• Worktree creation fails without plan
• Acceptance returns conversational hint
• PR creation fails without worktree

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"Right then. Let's get to it."

— Blue